> I actually despair about when my family members are forced into passkeys and then lose access to their accounts because they get a new device.

Both iOS and Android sync passkeys to their respective cloud accounts by default. (Of course, losing access to that account, sharing one across family members and causing confusion etc. are still concerns.)

The real problem is lock-in, as this effectively often prevents entire families from switching from iOS to Android or vice versa. I'd encourage anyone managing their family's tech setup to pick a platform-agnostic passkey implementation such as 1Password or Bitwarden for that reason.